What Is An “Access Control System”?
Simply defined, the term “access control” describes any technique used to control passage into or out of any area. The standard lock that uses a brass key may be thought of as a simple form of an “access control system”.
Over the years, access control systems have become more and more sophisticated. Today, the term “access control system” most often refers to a computer-based, electronic card access control system. The electronic card access control system uses a special “access card”, rather than a brass key, to permit access into the secured area.
When used within this document, the term “access control system” refers to an electronic card access control system.
Access control systems are most commonly used to control entry into exterior doors of buildings. Access control systems may also be used to control access into certain areas located within the interior of buildings.
The purpose of an access control system is to provide quick, convenient access to those persons who are authorized, while at the same time, restricting access to unauthorized people.
Basic Components of an Access Control System
Access control systems vary widely in type and complexity. However, most card access control systems consist of at least the following basic components:
The access card may be thought of as an electronic “key”. The access card is used by persons to gain access through the doors secured by the access control system. Each access card is uniquely encoded. Most access cards are approximately the same size as a standard credit card, and can easily be carried in a wallet or purse.
Card readers are the devices used to electronically “read” the access card. Card readers may be of the “insertion” type (which require insertion of the card into the reader), or may be of the “proximity” type (which only require that the card be held in a 3″ to 6″ proximity of the reader. Card readers are usually mounted on the exterior (non-secured) side of the door that they control.
Access Control Keypads
Access control keypads are devices which may be used in addition to or in place of card readers. The access control keypad has numeric keys which look similar to the keys on a touch-tone telephone.
The access control keypad requires that a person desiring to gain access enter a correct numeric code. When access control keypads are used in addition to card readers, both a valid card and the correct code must presented before entry is allowed.
Where access control keypads are used in place of card readers, only a correct code is required to gain entry.
Electric Lock Hardware
Electric lock hardware is the equipment that is used to electrically lock and unlock each door that is controlled by the access control system.
There are a wide variety of different types of electric lock hardware. These types include electric locks, electric strikes, electromagnetic locks, electric exit devices, and many others. The specific type and arrangement of hardware to be used on each door is determined based on the construction conditions at the door.
In almost all cases, the electric lock hardware is designed to control entrance into a building or secured space. To comply with building and fire codes, the electric lock hardware never restricts the ability to freely exit the building at any time.
Access Control Field Panels
Access control field panels (also known as “Intelligent Controllers”) are installed in each building where access control is to be provided. Card readers, electric lock hardware, and other access control devices are all connected to the access control field panels.
The access control field panels are used to process access control activity at the building level. The number of access control field panels to be provided in each building depends on the number of doors to be controlled. Access control field panels are usually installed in telephone, electrical, or communications closets.
Access Control Server Computer
The access control server computer is the “brain” of the access control system. The access control server computer serves as the central database and file manager for the access control system; and is responsible for recording system activity, and distributing information to and from the access control field panels.
Normally, a single access control server computer can be used to control a large number of card-reader controlled doors.
The access control server computer is usually a standard computer which runs special access control system application software. In most all cases, the computer is dedicated for full-time use with the access control system.